Selective switching system



April 22, 1952 A. LIBERMAN SELECTIVEVSWITCHING SYSTEM 5 Sheets-Sheet 1 Filed Nov. 9, 1949 A9 30 Z/ Z5 Z5 Z5 7 m M M v April 22, 1952 UBERMAN 2,594,043

SELECTIVE SWITCHING SYSTEM FiledNov. 9, 1949 3 Sheets-Sheet 3 /ZZ A53 AZU g /06 T mx Q57 1 .Q l M? //7 56 v T J //6 727 j m %7%% Patented Apr. 22, 1952 UNITED STATES PATENT OFFICE 2,594,043 SELECTIVE SWITCHING SYSTEM Arie Libermam Chicago, Ill. Application November 9, 1949, Serial No. 126,327

This invention relates to a switching system,

and more particularly to a switching system having primary switch means and secondary switch means for selecting certain terminals of the primary switch means.

An important feature of this invention is that 7 it provides an improved system enabling a standardized cabinet and set of switches to be used for intercommunicatlon systems of greatly differing numbers of stations; another feature of this invention is that it provides primary switch means having a plurality of simultaneously operable terminals and secondary switch means for selecting certain of said plurality of terminals, only the selected terminals being activated in accordance with the position of the secondary switch means; a further feature of the invention is that the primary switch means comprise at least one group of single-throw switches, the switches in each group having a common operating means; yet another feature of the invention is that the secondary switch means comprise at least one double-throw switch having a movable pole and a pair of stationary contacts, said stationary contacts being connected to the terminals of the primary switch means for activating only selected terminals in accordance with the position of said movable pole; still a further feature of the invention is that tertiary switch means may be connected to the secondary switch means, only a portion of the primary switch means being activated in accordance with the position of the secondary and tertiary switch means; an additional feature of the invention is that it provides a switching system particularly adapted for use in an intercommunication system wherein a large number of stations may be provided while utilizing a much smaller number of manual switching means; and yet a further feature of the invention is that it provides a switching system which may be used in intercommunication sys tems having a wide variation in the number and/or arrangement of stations employed while utilizing the same number of manual switch means regardless of the number and/or arrangement of stations employed.

Other features and advantages of the invention will be apparent from the following specification taken in connection with the accompanying drawings, in which:

Fig. 1 is a front elevational view of an inter-- communication station utilizing the invention;

' Fig. 2 is an end elevational view of the apparatus of Fig. 1; and

, Figs. 3A and 33 together comprise a schematic 2 Claims. (Cl. 177-353) 2 wiring diagram showing the improved switching system.

An intercommunication system of the' character illustrating an embodiment of this invention comprises a plurality of stations connected to each other to provide intercommunication. The term local station is herein employed merely to designate the particular station the operation of which is being disclosed; and the term "distant station is herein employed merely to designate other stations in the system, without regard to the actual location of these other stations. The stations may be 'so-called "master stations including an amplifier, or may be so-called staff stations which have no amplifier, but merely comprise a translating device (as a speaker-microphone) and switching means. A master station may communicate with a stall station or another master station, the voice of the operator of the master station being amplified at his local station and then being connected to a desired distant station through a switching system as will be herein disclosed.

- However, a staff station has no amplifier and generally may communicate (or at least originate a conversation) only with master stations (normally few in number) to which the staff station is connected, the amplifier in the master station being utilized to render audible the signal which originates at the staff station.

In certain intercommunicating systems means are provided wherein certain stations may be private"'-i. e., a station may be connected or arranged in such manner that sounds at that location can be heard only after that person moves'his talk-listen switch to talk position. Other stations in the same system may be so arranged, if desired, that they are non-private"--i; e., any master station making connection to that station through-operating the appropriate connector switch may hear anything at that' any act by the 55'- of switching devices for each unit manufactured,

at least up to any reasonable limit. Furthermore,

as a principal feature of the invention thev same number of manually operated switch devices for connecting in different distant stations are provided and utilized regardless of the number of stations in the system, and there may be many more stations in the s stemthan there are manual switch arrangements. The cabinet used in Fig. l may be utilized in a six, ten or twelve station arrangement for example; or the same cabinet withlt e. same s h g means may be u l d in a forty station arrangement as, illustrated, in Fig. 3;. Similarly, any lesser number of stations (as twenty. or thirty) may be connected in as desired andthe same cabinetmay be used, thus k g it o s le to t n a dfm e. man f ture and to. provide a small cabinet of modern design using the same parts regardless of the number of stations in the; system.

The basic principle of my improved arrangement is that it provides primary switch means having a plurality of simultaneously operable terminals and secondary switch means for selecting certain of said plurality of terminals together with connections. between the primary and secondary switch means; for activating only the selected terminals to connect the local station with a selected distantstation accordance with the position of the secondary switch means.

Referring to the drawings, Eig. 1 shows amaster station cabinet, it being understood that this station is connected, to a plurality of distantv sta-.

tions some of which may be master stations and som f wh h y e aff. stati nsin norm installation. The station shown in Fig. l is desig nated a local station merely because it is the station the operation of whichwillbe described.

The station comprises a cabinet III-housing an amplifier, speaker and microphone and switch ing arrangement. On the face of the cabinet ,is a control knob ,I I. which may be a combination on-' with either of stations 2, 12,22 or 32, and each of the remaining push buttons I5, IS, IT, I8, I9, 20, 2I and 22 (i. e., the first ten in all) may be utilized to connect the local station with any one of four distant stations as noted on the face of each push button. Of course, the local station being described itself utilizes one station number and is a part of the 40 station system. 7

Push button 23 may be best explained as an add lfl. switch; For example, when push button i3 alone is pushed the local station illustrated will be connected to distant station No. 4. When it pushed, these connections being explained in the disclosure of Fig. 3.

.. operator of the local station. purchaser of the intercornmunication system did Push button 24 may be considered as an add 20" switch, and pushing buttons IS and 24 will connect the local station with station 24. As disclosed later in connection with Fig. 3, pushing in one of the station push buttons together with both push buttons 23 and 25 will add 30. For example, if push buttons It, 23 and 24. are all pushed, the local station will be connected with distant station No. 34.

I am able, therefore, to connect the local station shown in Fig. 1 with any one of thirty-nine distant stations, while at the same. time providing only twelve push button switches for the lathe event the not want forty stations but wanted a lesser number as, for example, ten stations or twenty stations or thirty stations, the same cabinet provided with the same push buttons I3-2=t could be used.

' In this event each push button would only designate the stations which it is utilized with, and I provide paper tabs having the various station numbers thereon to cover a situation where a difierent number of stations are in the system.

If fewer stations are used, as twenty stations or ofi switchv and volume control knob, as; is well understood'in the art. A switch, bar 'I-2 operates a talk-listen switch more disclosed in Fig. 3, and across the face of the cabinet is a row of twelve push buttons I3, I4, I5, I6, I], I8. I9, 2Il, 2I, 22, 23 and 24. These push buttonsoperate the station selector switches and while, illustrated as push button switches, obviously othertypes of switches, as rotary selector switches for example. canbeutilized. Inasmuch as the station shown is assumed to baa part, of aforty station system, there are forty stations controlled by the twelve, push buttons 1 panel:- s. shown. n F 1,. he fir p tt n i i ed as; pushed. in o connect h ca tatigaw an qneo o r distant stations numbered 1, 11, 2i and 31, as determined by the. selector system hereinafter described, each station in the system being assigned a number for convenience. Similarly, the second push button mayv be utilized to c'onnect less, one of the push buttons, as 24, may be utilized solely to provide paging as is well understood in the art; or even with a larger number of stations in the system it may provide paging when none of the station buttons is actuated,

Furthermore, as the description of 3 proceeds, itwill be obvious that the same cabinet and push button arrangement of Fig. 1 can be utilized if desired to provide for 5Q, 60 or any higher number of stations merely, by adding contacts to the switches shown in Fig. 3,

Referring now to Fig. 3, the talk-listen switch I2 comprises a ganged combination of switches including six single pole double-throw switches 30, 3|, 32, 33, 34 and 35, and two singlepole singlethrow switches 36 and 31, all the switches 3,0 31 being operated simultaneously by a single control. The push button I3 comprises a single control for simultaneously operating four double-pole, singlethrow switches 4.0, ll, 42 and 43,; the push buttonv I4 acts as a single control for four double-pole single-throw switches is to iii; and similarly, push buttons I5, I6, I], I8 and IQ each provide a common'operating means for a group of four double-pole single-throw switches which are not shown in Fig. 3 in order to simplify the. drawing. The push button 20 is shown as comprising a common operating means for a groupof four double-pole single-throw switches 50,5 4, 52 and 53; push button 2| as comprising a carnmon operating means for a group of fourdouble-pole single-throw switches 55, 5t, 57 and 58, and push button 22 as comprising a common operating meansifor another group of four double-pole single-throw switches 60, 6|, 62'and 63. As noted earlier all the switches may, if desired, be of some other type, as rotary selector switches.

Push button 23 provides a common operating means for four double-pole double-throw switches 65, 66, 61 and 68; and push button 24 comprises a common operating means for two double-pole double-throw switches H1 and H. An amplifier is also within the cabinetJU, this amplifier (illustrated in block form since it may be of conventional design) having a pair of input leads [6 and TI and a pair of output leads l8 and 19. A conventional combination speaker-microphone 80 is also in the cabinet in.

The talk-listen switching arrangement comprising the ganged switches 30-3! is illustrated as being in talk position. This is the position which would be assumed if the touch bar l2 of Fig. 1 were pushed down, and when the touch bar I2 is released it assumes the position shown in Fig. 1, which throws the switches 30-31 to the position other than that shown in the drawings.

Each of the single-throw switches associated with the push button l3-22 has a pair of upper terminals (as the parts are positioned in the drawings) for connection to the local station with which the switches are associated, and each switch has a pair of lower terminals for connection to a distant station. For example, the lower switch 40 would be connected to distant station No. 1; the lower terminals of switch 4| would be connected to distant station No. 11; the lower terminals of switch 42 would be connected to distant station No. 21; and the lower terminals of switch 43 would be connected to distant station No. 31. All of these connections are illustrated as conventional two-wire connections which may be completed through a junction box and cable.

While any desired arrangement of private and non-private stations may be made, as is more fully described in 'my copending application Serial No. 129,411, filed November 25, 1949, it is assumed that the stations controlled by push buttons 13 and I4 are connected for private operation and the stations controlled by buttons 20, 2| and 22 are connected for non-private operation. All of the switches associated with the push buttons l3-22 are connected to the local station through the switches associated with the push buttons 23 and 24, push button 23 being operated when it is desired to add ten to the number of the station normally controlled by any of the push buttons 13-22; push button 24 being operated when it is desired to add and both push buttons 23 and 24 being operated when it is desired to add 30 to the number or the station normally controlled by any one of the push buttons l3-22.

Referring to the push button 23, the switch 55 is utilized to add ten in affecting those stations connected for private conversation; the switch 66 is utilized to add ten afiecting those stations connected for non-private conversation; the switch 6! is utilized when twenty or thirty are added affecting those stations connected for private conversation; and the switch 68 is utilized when twenty or thirty are added affecting those stations connected for non-private conversation.

Referring to the push button 24, the switch 10 is utilized for adding twenty or thirty afiecting those stations connected for private conversation;

and the switch H is utilized for adding twenty or thirty afiecting those stations connected for nonprivate conversations.

As noted earlier, the station is shown with the talk-listen switch in talk position. If the operator of the local station wishes to talk to distant station No. 2 (it being assumed, of course, that the amplifier is supplied with proper operating voltages from a power pack connected to a source of voltage, as for example, to a commercial 110 volt system) the operator merely pushes push button 14, thus closing switches 44, 45, 46 and 41. However, the local station is connected only with one of these distant stationsstation 2 as the parts are shown. This connection may be traced as follows: a lead 81 connects the microphone with the movable pole of the switch 30, which, in talk position, engages the left contact of said switch, this left contact being connected by a lead 82 to the input lead '16 of the amplifier. Another lead" 83 connects the microphone with the movable pole of switch 32 which engages the left stationary contact of this switch, and this stationary contact is connected by a lead 84 with the amplifier input lead 11. The voice of the operator is amplified in the amplifier l! and the voice signal appears across leads 13 and '19 which respectively connect with the movable pole of switches 34 and 35. The closed stationary contact of switch 34 connects with a common-lead 85 and the closed stationary contact of the switch 35 connects with a complementary common lead 86, these being the common leads of the private type of connection. The leads 85 and 85 connect with the movable poles of switch 16. The two upper stationary contacts of switch 1!] are connected by means of respective leads 8! and 83 to the movable poles of switch 65; and the upper stationary contacts of switch 65 are connected by means of leads 89 and 90 to the upper contacts of one of the switches in each group of switcheswhich are operated by station selecting push buttons !3-22 and which are connected for private conversation. In Fig. 3A the leads 8!! and 90 are shown as connecting with the upper terminals of switches 40 and 44.

is unaffected. Switch 44 (as well as switches 45,

46 and 4'!) is assumed to be closed so that the circuit is complete through the switch 44 to dis tant station No. 2. None of the other switches 45, 46 or 47 are affected despite the fact that these switches are closed since none of these switches and 68- from the position shown to the other position wherein the movable poles of these switches close with the lower contacts of the" switches. Now with the parts in this position, the leads 8'! and 83 would no longer connect with the leads 89 and 90, and the switches 40 and 44 would be disconnected from the local station. However, the lower stationary contacts of the switch 65 are connected by respective leads 9! and 92 to the upper contacts of another switch in each group of station selector switches, hereshown as switch 4| in the group operated by push button I3 and as switch 45 in the group operated by push button l4. Withswitch 55 moved to the position other than that illustrated, the local station would be connected with distant station No. 12, leads from the lower ter-"f minals of switch 45 making this connection with distant station No. 12.

On the other hand, assuming the operator wishes to talk to distant station No. 22, he would,

How-' ever, switch it is open so distant station No. 1,

c eeses of: course, operate push button. I4. as before, but instead of operating push button 23 he would leave, the switches associated with this push button in the position shown in Fig. 3 and would instead operate push button 24 movin 7 the switches It and II to the position other than that shown in the drawing so that the. movable poles. of these switches close with the. lower contacts thereof. This action would disconnect the leads 8,? and 88 at the switch I and would connect the leads 85 and 86 to leads 93 and 941 which connect with the respective movable poles. ofv switch 61. With this switch in the position as. shown in Fig. 3, another one of the switches. in each. group of' private selector switches. is connected to the local station. Leads 65. and 96. connect the upper contacts of switch 51 with the upper terminals. of switches 52 and 46,. so that. thelocalstation would be connected in the. illustration given, to station 22 through switch 46.

Inf the event the operator wishes to talk to. distant station No. 32 he would operate push buttons I4. 23 and 2d. The circuit would be the. same as just above described down through leads 53. and 9 5. However, now the movable polesoi switch 61 closes the lower contacts of saidswitch, andthese contacts are connected by leads 2:? and: 98.150. the fourth switch. of each group of private. stations, here shown as switches 43 and 43. In the. illustration givenswitch E3 is open while.- switch lis closed and its lower terminals. are connected, with distant station No. 32.

Similar connections are made to the. nonprivate stations, here shown as those stations selected by. push buttons 26, 2| and 22. The. nonprivate common leads are designated ltll and I01 respectively. The lead It!) is connected between the movable pole of switch 3i of the talklisten switch means and a movable pole. of the add 20 switch II. The left contact of switch I which is closed in talk position is connected to lead 8'6 by means of a lead I02. The lead llll extendsbetween the movable pole of switch 33 of the talk-listen switch means and the other movable pole, of the doubleepole double-throw switch II. The lead It is connected to the common private lead 85 by means of a lead I03 which extends. from the left contact of the switch 33 to the lead 85. Consequently, the voice signal appears acros the leads I60 and NH.

The upper contacts of the switch II are connected by leads I and N36 to they respectivemovable poles of switch 66 and the lower contacts of switch II are connected by means of' leads I67 and I08 to the respective movable poles of the switch 68. The upper stationary contacts of switch 66 are connected by leads H0. and I l I to the terminals of a first switch infeach group of selector switches connected for nonprivate conversation, here shown as switches 56, 55 and 60 and the lower stationary contacts of switch 66 are connected by leads H2 and; M3. to the terminals of a econd switch of each group of selector switches connected for non-private conversation, here shown as switches 5|, 56 and 6!. It should be, noted that the switch 68 is exactly similar to the switch 65 except, that: switch 66 is in the non-private circuit while. switch 65 is in the private circuit. The upper stationary contact of switch 68 are connected by leads H4 and H5 to a third switch of each group of selector switches connected for nonprivate conversation, here shown as switches. 52. 5.1- and 62; and the lower stationary contacts. of switch 68 are connected by leads. [I 6' and. H! to a fourth switch of each. group of selector switches connected for non-private. conversation, here shown as switches 53, 58 and. 63.. It is thus seen that the switch 68 is similar to the switch 61 except. that switch 61 is in the private circuit while switch 68 is in the non-private circuit; and switch II is similar to I6 except that switch 10' i in the private circuit and switch II is in the nonrprivate circuit.

When. the operator of the local station wishes to listen to a distant station he merely connects to the desired distant station by pushing one of the selector buttons Iii-22v and if the number of the desired station is above ten, one or both. of the. add ten or add 20 buttons as above described. and pushes the touch bar I2 to move the switches 351-31 to the position other than that shown in the drawing. This connects the speaker 88. to the output of the amplifier and connects thev signal leads (I66 and It!) to the input of the amplifier. The speaker lead BI is connected to the output of the amplifier through the right contact of switch 30, through a lead I-2l3-,;and' through the right contact of switch 35 and the amplifier output lead 19. The speaker lead, 83 is connected to the amplifier output through the right contact of switch 32 through leadIZl, and through the right contact of switch 3'4 and lead IS. A terminal I22 i connected to the lead 126' and a terminal E23 is connected to the lead I2I to provide points of connection for the incoming signal from a master station, inasmuch as this signal has already been amplified at the distant master station and normally need'not be amplified further.

However, if the local station is connected to a distant: staff station, no amplification of the incoming signal is provided on the distant stafiz station. The incoming signal from the staff station may be connected to terminals 525 and I26 which are connected to the leads l0! and IIW through the respective switches 36 and 37. Inasmuch as the local station illustrated is a master station it can communicate with any other master station in the system, and therefore, the distant master stations are connected to the local station through the switching systemabove described. However, a few stai f stations maybe connected to the master through the terminals I 25 and I26 and these staff stations may talk only to the master station to which they are connected. With the talk-listen switch in the position illustrated of course the staff: stations connected to terminals I25 and I-26zcannot converse with the local master station. However, when the tall 1isten switch is thrown tothe listen position switches 36 and 31 are closed. Terminal. I25 is connected to the amplifier input through switch 36 through a portion of lead IM, through the right contact of switch 3'3,-and through a lead I21 which connects with amplifier input lead ll. Terminal 126. is connected to the amplifier input through the switch 31, a portion of lead I08, the right contact-of switch 3!, and a lead E28 which connects with amplifier input lead 16. With. these connections the signal from the stali station is amplified in the amplifier I5 and is connected to the speaker 86. I

The provision of the switching arrangement including the add, ten push button 23 and its associated switches and the add 20 push button 24 and its associated switches makes, it possible to incorporate any normally desired number of. master. and staff stations in an intercommunication system, and the local station with which the switching arrangement above described is associated can communicate with any desired distant master or stafi" station while utilizing only the twelve push buttons as shown in Fig. 1. If desired, additional contacts can be added to the switches and the number of stations in the system may be increased within practical limits. The cabinet design and construction and the mechanical switching arrangements may be standardized for manufacture on a mass production basis regardless of the fact that the systems may vary in number and arrangements of stations, and the cabinet may be kept small because twelve push buttons will handle any desired number of stations.

While I have shown and described certain embodiments of my invention, it is to be understood that it is capable of many modifications. Changes, therefore, in the construction and arrangement may be made without departing from the spirit and scope of the invention as disclosed in the appended claims.

I claim:

1. In an intercommunication system wherein a local station may be connected to a plurality of distant stations, a, manually operable switching system of the character described for connecting said local station to a selected one of a plurality of distant stations, comprising: manually operable primary switch means mechanically maintained in either of two limiting positions and comprising a number of groups of single-throw switches, each group comprising four of said switches and having a common operating means, each switch having a movable member and a plurality of fixed terminals; manually operable secondary switch means comprising two double-throw switches each having a movable member and a plurality of fixed terminals, said movable members having common operating means; manually operable tertiary switch means comprising one double-throw switch having a movable member and a plurality of fixed terminals; electrical connections between each of said single-throw switches and one of said distant stations; electrical connections between each of said single-throw switches in each group and the fixed terminals of said secondary switch means; electrical connections between the movable members of said secondary switch means and the fixed terminals of said tertiary switch means; and electrical connections between the movable member of said tertiary switch means and said local station.

2. In an intercommunication system wherein a local station may be connected to a, plurality of distant stations, a manually operable switching system of the character described for connecting said local station to a selected distant station, comprising: manually operable primary switch means mechanically maintained in either of two limiting positions and comprising a number of groups of single-throw switches, each group comprising two of said switches and having a common operating means, each switch having a movable member and a plurality of fixed terminals; manually operable secondary switch means comprising one double-throw switch having a movable member and a plurality of fixed terminals; electrical connections between each of said single-throw switches and one of said distant stations; electrical connections between each of said single-throw switches in each group and the fixed terminals of said secondary switch means; and electrical connections between the movable member of said secondary switch means and said local station.

ARIE LIBERMAN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 801,173 Barclay Oct. 3, 1905 970,367 Blos Sept. 13, 1910 2,279,009 Nichols Apr. 7, 1942 

